1. Technical Field
The present invention relates to a concentration determination apparatus and a concentration determination method that are suitable for a determination of a concentration of a measured component contained in a living body tissue, particularly, a concentration of glucose contained in skin.
This application claims priority to and the benefits of Japanese Patent Application No. 2011-137316 filed on Jun. 21, 2011, the disclosure of which being incorporated herein by reference.
2. Related Art
Traditionally, measurement of a blood sugar level has been performed by taking a blood sample from, for example, a fingertip and measuring enzyme activity for glucose in the blood. However, in such a method of measuring a blood sugar level, blood must be collected from, for example, the fingertip to perform the measurement and taking the blood sample requires effort and is painful. Also, a measurement tip for adhering blood is necessary. Accordingly, there is a need for a non-invasive blood sugar level measurement method that does not require that a blood sample be taken.
For example, an apparatus for measuring a glucose concentration in a living body disclosed in Japanese Patent Application, First Publication No. 2001-29972 has been known as an example of realizing the non-invasive blood sugar level measurement as described above. In general, an apparatus in which, when near-infrared spectroscopic analysis of a solution or a sample having high moisture content is performed, for example, a shift of a spectrum of the sample due to temperature change is greatly changed, similar to a spectrum of water, and an influence of temperature is not negligible in quantitative analysis has been known. In the measurement apparatus disclosed in Japanese Patent Application, First Publication No. 2001-299727, when a glucose concentration is measured, a temperature of a target tissue is controlled to have a constant value by a temperature control means, thereby quantifying the target component with higher measurement accuracy.
Further, for example, a double-beam Fourier transform infrared spectroscopic method for detecting a specific component in a sample having low transmittance disclosed in Published Japanese Translation of a PCT application No. 2003-535329 has been known. In the above-described infrared spectroscopic analysis, arranging a material containing water as a reference material for a measuring object is shown. Accordingly, the target component may be quantified with higher measurement accuracy.